French Patent No. 88 16 053 describes a culture dish intended for culturing microorganisms, comprising a receptacle which is covered by a lid and on the bottom of which there is disposed a layer of a culture medium and a spreader emerging from an internal face of the lid and intended to spread an inoculum over the layer. The lid is mounted movably on the receptacle so as to be able to transfer from a depositing position, in which the spreader is distant from the layer, to a spreading position in which it touches the layer.
After having performed the spreading and having returned to the depositing position, it is possible to pass involuntarily from the depositing position to the spreading position. The raised parts of colonies which are formed are thus scraped, which vitiates the subsequent evaluation.